1. Field of the Invention
The present invention relates to a vehicle headlamp that is provided with a semiconductor-type light source and a reflection surface. In other words, the present invention relates to a vehicle headlamp of a landscape placement type of which light emitting chips of a semiconductor-type light source are provided in a reference optical axis direction (in a lateral direction), the vehicle headlamp also serving as a vehicle headlamp of a reflection type (reflector type) of which light from the semiconductor-type light source is reflected on a reflection surface to thereby emit a predetermined light distribution pattern forward of a vehicle.
2. Description of the Related Art
A vehicle headlamp of such type is conventionally known (for example, Japanese Unexamined Patent Application Publication No. 2011-34875). Hereinafter, a conventional vehicle headlamp will be described. The conventional vehicle headlamp is provided with an LED light source, a first reflection surface, and a second reflection surface. The conventional vehicle headlamp is provided in such a manner that light beams from the LED light source are respectively emitted forward of a vehicle as a first partial light distribution pattern that is reflected on the first reflection surface, the pattern having a horizontal cutoff line, and as a second partial light distribution pattern that is reflected on the second reflection surface, the pattern having an oblique cutoff line. In other words, the conventional vehicle headlamp is adapted to emit a light distribution pattern for low beam (a light distribution pattern for passing).
However, the conventional vehicle headlamp is adapted to divide a reflection surface into a first reflection surface that is proximal to the LED light source and a second reflection surface that is distant from the LED light source. Therefore, in the conventional vehicle headlamp, if a light distribution pattern for high beam (a light distribution pattern for cruising) is emitted forward of a vehicle in place of the light distribution pattern for low beam, as shown in FIG. 8, there may be produced a light distribution pattern for high beam HPB (including a high luminous intensity area SPA) that is not transversely symmetrical to an optical axis (a vertical line VU-VD from the top to the bottom of a screen in FIG. 8). As described above, in the conventional vehicle headlamp, it is difficult to form an approximately ideal light distribution pattern for high beam HPA (including a high luminous intensity area SPA) shown in FIG. 7. It is to be noted that the approximately ideal light distribution pattern for high beam HPA, as shown in FIG. 7, is a light distribution pattern for high beam that is substantially transversely symmetrical to the optical axis (the vertical line VU-VD from the top to the bottom of a screen in FIG. 7).
The present invention has been made in order to solve the above described problem that in the conventional vehicle headlamp, it is difficult to form an approximately ideal light distribution pattern for high beam.